The present invention relates to a photographic apparatus in general, and in particular to a photographic apparatus of the type wherein a strip-shaped material is to be advanced by means of a travelling leader tape.
In many instances it is necessary to advance photographic material, usually in strip-shaped form, through all or part of a photographic apparatus. In some cases it is necessary for this purpose to employ a travelling leader tape. This is done if the leading end of a strip of material is to enter the apparatus or a part thereof through an inlet which is constructed to prevent access of light to the interior, or if there is simply no way in which the leading end of the strip-shaped material can be manually inserted into the apparatus or the particular part thereof. Leader tapes are, accordingly, widely -- but not exclusively -- used for pulling strip-shaped photographic material through a series of baths in a developing apparatus.
In a apparatus in which leader tapes are employed, it is customary to provide a carrier for the strip-shaped material on or to which the material can be secured. Such carriers are formed with a channel that is defined by two transversely spaced U-shaped hook-shaped configurations which are transversely spaced from one another by a distance slightly smaller than the width of the leader tape. The leader tape is manually inserted into the channel so that upon insertion it becomes slightly bowed and sprung in the channel, i.e. in its tendency to flatten out -- the tape is usually of synthetic plastic material -- it presses against the surfaces bounding the channel and thus establishes a mechanical connection with the carrier, taking the latter along. In the older type of apparatus using this leader tape approach, the just-described arrangement has been generally satisfactory. Not so, however, in the more modern types of apparatus wherein the strip-shaped material is to be transported at speeds which are usually in excess of 8 meters per minute and at the present time and stage of development may be as high as 15 meters per minute. This means, of course, that the leader tape must travel at a corresponding speed and, this in turn, clearly precludes any possibility of establishing a manual connection between the carriers and the travelling leader tape. While it has been proposed to provide such an apparatus with a storage reservoir for the leader tape, making it possible to actually stop the leader tape at a certain point outside the apparatus in order to permit the respective carriers to be connected to it, it has been found that a storage reservoir capable of storing efficient of the leader tape so that the portion located outside the apparatus can be temporarily halted, is so voluminous and structurally complicated and therefore expensive, as to make this solution impractical for commerically utilizable equipment.